Byrd n 1: English organist and composer of church music; master of 16th century polyphony; was granted a monopoly in music printing with Thomas Tallis (1543-1623) [syn: {William Byrd}] 2: explorer and United States naval officer; led expeditions to explore Antarctica (1888-1957) [syn: {Richard E. Byrd}, {Richard Evelyn Byrd}, {Admiral Byrd}]